[llvm] r352888 - [llvm-objcopy][NFC] More error propagation (executeObjcopyOnArchive)

[Jordan Rupprecht via llvm-commits]

Author: rupprecht
Date: Fri Feb  1 09:08:07 2019
New Revision: 352888

URL: http://llvm.org/viewvc/llvm-project?rev=352888&view=rev
Log:
[llvm-objcopy][NFC] More error propagation (executeObjcopyOnArchive)

Summary:
Replace some reportError() calls with error propagation that was missed from rL352625.

Note this also adds an error check during Archive iteration that was being hidden by a different error check before:

```
  for (const Archive::Child &Child : Ar.children(Err)) {
    Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
    if (!ChildOrErr)
      // This aborts, so Err is never checked
      reportError(Ar.getFileName(), ChildOrErr.takeError());
```

Err is being checked after the loop, so during happy runs, everything is fine. But when reportError is changed to return the error instead of aborting, the fact that Err is never checked is now noticed in tests that trigger an error during the loop.

Reviewers: jhenderson, dblaikie, alexshap

Reviewed By: dblaikie

Subscribers: llvm-commits, lhames, jakehehrlich

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57462

Modified:
    llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp

Modified: llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp?rev=352888&r1=352887&r2=352888&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp Fri Feb  1 09:08:07 2019
@@ -96,10 +96,13 @@ static Error deepWriteArchive(StringRef
                               ArrayRef<NewArchiveMember> NewMembers,
                               bool WriteSymtab, object::Archive::Kind Kind,
                               bool Deterministic, bool Thin) {
-  Error E =
-      writeArchive(ArcName, NewMembers, WriteSymtab, Kind, Deterministic, Thin);
-  if (!Thin || E)
-    return E;
+  if (Error E = writeArchive(ArcName, NewMembers, WriteSymtab, Kind,
+                             Deterministic, Thin))
+    return createFileError(ArcName, std::move(E));
+
+  if (!Thin)
+    return Error::success();
+
   for (const NewArchiveMember &Member : NewMembers) {
     // Internally, FileBuffer will use the buffer created by
     // FileOutputBuffer::create, for regular files (that is the case for
@@ -149,14 +152,17 @@ static Error executeObjcopyOnArchive(con
   std::vector<NewArchiveMember> NewArchiveMembers;
   Error Err = Error::success();
   for (const Archive::Child &Child : Ar.children(Err)) {
+    // FIXME: Archive::child_iterator requires that Err be checked *during* loop
+    // iteration, and hence does not allow early returns.
+    cantFail(std::move(Err));
     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
     if (!ChildOrErr)
-      reportError(Ar.getFileName(), ChildOrErr.takeError());
+      return createFileError(Ar.getFileName(), ChildOrErr.takeError());
     Binary *Bin = ChildOrErr->get();
 
     Expected<StringRef> ChildNameOrErr = Child.getName();
     if (!ChildNameOrErr)
-      reportError(Ar.getFileName(), ChildNameOrErr.takeError());
+      return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
 
     MemBuffer MB(ChildNameOrErr.get());
     if (Error E = executeObjcopyOnBinary(Config, *Bin, MB))
@@ -165,19 +171,17 @@ static Error executeObjcopyOnArchive(con
     Expected<NewArchiveMember> Member =
         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
     if (!Member)
-      reportError(Ar.getFileName(), Member.takeError());
+      return createFileError(Ar.getFileName(), Member.takeError());
     Member->Buf = MB.releaseMemoryBuffer();
     Member->MemberName = Member->Buf->getBufferIdentifier();
     NewArchiveMembers.push_back(std::move(*Member));
   }
-
   if (Err)
-    reportError(Config.InputFilename, std::move(Err));
-  if (Error E = deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
-                                 Ar.hasSymbolTable(), Ar.kind(),
-                                 Config.DeterministicArchives, Ar.isThin()))
-    reportError(Config.OutputFilename, std::move(E));
-  return Error::success();
+    return createFileError(Config.InputFilename, std::move(Err));
+
+  return deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
+                          Ar.hasSymbolTable(), Ar.kind(),
+                          Config.DeterministicArchives, Ar.isThin());
 }
 
 static void restoreDateOnFile(StringRef Filename,